The stars hung out backstage at Bridgestone Arena in Nashville, Tennessee. Mars is currently on his 24K Magic Tour, which will end at Aloha Stadium in Hawaii in November.

Back in August, the “Shape of You” singer, 27, teased a secret collaboration with Mars. “I was in the studio the other day with him,” he told Entertainment Tonight at the time. “We know each other very well. We hangout.”

“Taylor, the AMA nominations came out. It’s me, you and Drake. You’re going to win,” Sheeran said during a hike last month, which was filmed by Swift. They later chimed in together: “Drake’s going to win.”

The American Music Awards airs on Tuesday, October 9, on ABC at 8 p.m. ET.